Journal articles: 'Propagation Optique'

1

Dulac, Anne-Val�rie. "De la propagation en milieu transparent�: lumi�res de l�optique �lisab�thaine." Sigila N�25, no. 1 (2010): 39. http://dx.doi.org/10.3917/sigila.025.0039.

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Barthelemy, A., S. Maneuf, and C. Froehly. "Propagation soliton et auto-confinement de faisceaux laser par non linearité optique de kerr." Optics Communications 55, no. 3 (September 1985): 201–6. http://dx.doi.org/10.1016/0030-4018(85)90047-1.

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3

Simon, Gérard. "L'optique d'ibn al-haytham et la tradition ptoléméenne." Arabic Sciences and Philosophy 2, no. 2 (September 1992): 203–35. http://dx.doi.org/10.1017/s0957423900001648.

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Quand on compare l'Optique d'Ibn al-Haytham (Alhazen) à celle de Ptolémée, on rencontre des innovations à coup sûr capitales, et qui chacune mériterait une analyse particulière: étude expérimentale de la propagation rectiligne de la lumière, nouvelle théorie de la vision fondée sur la réception dans l'œil de rayons lumineux, recherche du lien entre l'anatomie de 1'œil et sa fonction optique, preuve expérimentale que la réfraction joue un rôle important dans la vision, et j'en passe: les dimensions d'un article de revue n'y suffiraient pas. Aussi bien mon but est-il plus global et plus synthétique. Il consiste à tenter de faire le point sur ce qu'est devenue, après Ibn al-Haytham, l'insertion de l'optique dans le système des savoirs qui lui sont connectès, en comparant cette insertion à ce qu'elle était au temps de Ptolémée, c'est-à-dire dans l'œuvre de référence (plus encore que celle d'Euclide et du pseudo-Euclide) reçae et travaillée par lui.

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Nicolai, Alexander, and Jantje Halberstadt. "La diffusion internationale d’idées commerciales." Revue internationale P.M.E. 21, no. 3-4 (September 18, 2009): 117–43. http://dx.doi.org/10.7202/038037ar.

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Résumé Traditionnellement, la recherche en entrepreneuriat s’intéresse davantage aux idées commerciales innovantes qu’aux créations d’entreprises qui ont pour objet l’imitation de concepts déjà existants. Cependant, la plupart des créations d’entreprises - y compris celles qui sont orientées vers une croissance rapide - reposent sur l’adoption ou la modification de modèles déjà existants. Différentes raisons expliquent le fait que les stratégies d’imitation ont gagné de l’importance dans les dernières décennies. En effet, grâce à la globalisation des marchés et à l’amélioration des technologies de l’information et de la communication, non seulement les produits et les technologies se diffusent plus facilement, mais aussi l’information. Conséquemment, cela facilite la propagation internationale d’idées. L’objectif de cette contribution est de soulever les questions centrales qui se posent dans le contexte de cette diffusion internationale d’idées commerciales et de les résumer dans un programme de recherche. Dans cette optique, cela consiste à éclairer l’intersection entre la recherche en entrepreneuriat et la recherche sur la diffusion d’idées déjà existantes. À l’aide d’un schéma du processus de diffusion, sept domaines de recherche se trouvant à l’intersection de ces deux domaines sont mis en évidence. La question de l’origine des idées commerciales et les types de diffusion semblent être d’une importance particulière. De plus, nous relevons différents groupes de facteurs, allant des caractéristiques d’adoption, de l’utilisation de réseaux jusqu’aux facteurs environnementaux, qui influencent la diffusion et la réussite d’idées imitées.

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Kim. "Development of Optimum Traffic Safety Evaluation Model Using the Back-Propagation Algorithm." Journal of the Korean Society of Civil Engineers 35, no. 3 (2015): 679. http://dx.doi.org/10.12652/ksce.2015.35.3.0679.

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Zhao, Daomu, Jiugao Zhu, and Shaomin Wang. "Azimuthally polarized Bessel - Gauss beam propagation through axisymmetric optical systems." Journal of Optics 28, no. 1 (February 1997): 3–5. http://dx.doi.org/10.1088/0150-536x/28/1/002.

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7

Liu, Linong, and Jianfeng Zhang. "3D wavefield extrapolation with optimum split-step Fourier method." GEOPHYSICS 71, no. 3 (May 2006): T95—T108. http://dx.doi.org/10.1190/1.2197493.

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A one-way propagator is proposed for more accurately modeling wide-angle wavefields in the presence of severe lateral variations of the velocity. The method adds a higher-order correction to improve the split-step Fourier method by directly designing a cascaded operator that matches the exact phase-shift operator of a varying velocity. Using an optimization scheme, the coefficients in the cascaded operator are determined according to the local velocity distribution and the prescribed angular range of wavefield propagation. The proposed algorithm is implemented alternately in spatial and wavenumber domains using fast Fourier transforms, as in the split-step Fourier and generalized-screen methods. This algorithm can achieve higher accuracy than the generalized-screen method for wide-angle wavefields, although the same numerical scheme is used with comparable computational cost. No extra error arises for the proposed algorithm when used for 3D wave propagation, in contrast to methods that introduce an implicit finite–difference higher-order correction to the split-step Fourier method, such as the Fourier finite difference (FFD) and wide-angle screen methods. A detailed comparison of the proposed one-way propagator with the split-step Fourier, generalized-screen, and FFD methods is presented. The 2D Marmousi and 3D SEG/EAEG overthrust data sets are used to test the prestack depth-migration schemes developed based on the proposed one-way propagators.

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Escoubas, Ludovic, Stéphane Tisserand, and Alexandre Gatto. "The balance of losses in optical coatings by absorption and guided propogation attenuation measurements." Journal of Optics 29, no. 1 (February 1998): 40–48. http://dx.doi.org/10.1088/0150-536x/29/1/007.

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9

Blanco, Carlos A., Julia Rayo, and José M. Giralda. "Improving Industrial Full-Scale Production of Baker's Yeast by Optimizing Aeration Control." Journal of AOAC INTERNATIONAL 91, no. 3 (May 1, 2008): 607–13. http://dx.doi.org/10.1093/jaoac/91.3.607.

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Abstract This work analyzes the control of optimum dissolved oxygen of an industrial fed-batch procedure in which baker's yeast (Saccharomyces cerevisiae) is grown under aerobic conditions. Sugar oxidative metabolism was controlled by monitoring aeration, molasses flows, and yeast concentration in the propagator along the later stage of the propagation, and keeping pH and temperature under controlled conditions. A large number of fed-batch growth experiments were performed in the tank for a period of 16 h, for each of the 3 manufactured commercial products. For optimization and control of cultivations, the growth and metabolite formation were quantified through measurement of specific growth and ethanol concentration. Data were adjusted to a model of multiple lineal regression, and correlations representing dissolved oxygen as a function of aeration, molasses, yeast concentration in the broth, temperature, and pH were obtained. The actual influence of each variable was consistent with the mathematical model, further justified by significant levels of each variable, and optimum aeration profile during the yeast propagation was found.

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10

Hoffman, David K., Mark Arnold, and Donald J. Kouri. "Properties of the optimum distributed approximating function class propagator for discretized and continuous wave packet propagations." Journal of Physical Chemistry 96, no. 16 (August 1992): 6539–45. http://dx.doi.org/10.1021/j100195a007.

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HOLBERG, O. "TOWARDS OPTIMUM ONE-WAY WAVE PROPAGATION1." Geophysical Prospecting 36, no. 2 (February 1988): 99–114. http://dx.doi.org/10.1111/j.1365-2478.1988.tb02154.x.

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Nemtsova, Ye V., A. V. Harin, and I. A. Razlugo. "THE INFLUENCE OF SILICON DIOXIDE «KOVELOS-SORB» ON GROWTH CHARACHTERISTICS OF RHODODENDRON ROSEUM (LOISEL.) REHDER CULTIVATED IN VITRO." Bulletin of Nizhnevartovsk State University, no. 1 (December 15, 2020): 48–55. http://dx.doi.org/10.36906/2311-4444/20-1/08.

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The article reveals a stimulating effect of synthetic amorphous silicon dioxide on growth parameters Rhododendron roseum (Loisel.) Rehder, propagating itself in vitro . The purpose of this study was to identify the optimum composition of culture medium on the basis of amorphous silica ‘Kovelos-Sorb’, used for clonal micropropagation of rhododendrons. It was established that it is preferable to add to Anderson culture medium 100 mg/L of amorphous silicon dioxide, which stimulated the growth of mericlone germs Rhododendron roseum (Loisel.) Rehder. In order to stimulate propagation and for receiving a vast amount of propagating material, it was optimal to use Anderson medium which contained 50 mg/L of amorphous silicon dioxide. For establishment of regenerative plants Rhododendron roseum (Loisel.) Rehder in vitro, it was optimal to use Anderson medium which contained synthetic amorphous silicon dioxide in amounts of 50-150 mg/L combined with indoleacetic acid in amounts of 1.5 mg/L.

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13

Serra, M. "Optimum beam design based on fatigue crack propagation." Structural and Multidisciplinary Optimization 19, no. 2 (April 2000): 159–63. http://dx.doi.org/10.1007/s001580050097.

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Burinskaya, T. M. "Ray tracing model of the auroral kilometric radiation generation in the 3-D plasma cavity." Annales Geophysicae 31, no. 10 (October 7, 2013): 1645–52. http://dx.doi.org/10.5194/angeo-31-1645-2013.

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Abstract. Propagation and amplification of the auroral kilometric radiation (AKR) in a three-dimensional plasma cavity is investigated using the approximation of the geometrical optics, and taking into account both the slightly relativistic electrons propagating inside a cavity and the background cold electrons. It is shown that the global magnetic field inhomogeneity plays a key role in a wave escape from a thin plasma cavity. The main contribution to the AKR spectrum is made by waves initially generated with the component of group velocity directed to the Earth and with the optimum relationship between the wave vector components, controlling the value of the linear grow rate and duration of the ray lifetime inside a source.

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15

Bendjebbour, Mohammed, Abdellatif Cherifi, and Benamar Bouhafs. "Analysis of Coupled Surface Plasmon in LHM Mediated Dielectric Gap Multilayer Structure." Photonic Sensors 10, no. 2 (December 21, 2019): 113–22. http://dx.doi.org/10.1007/s13320-019-0568-3.

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AbstractThe purpose of this work is to investigate theoretically the characteristics of confined electromagnetic modes propagating along the interfaces of a multilayer device. This one dimensional (ID) sensor is formed by stacking a left-handed material (LHM) layer between a SiCt2-glass prism and a dielectric gap layer in contact with gold (Au). The results indicate that the total thickness of the LHM layer and dielectric gap, in optimum conditions, give the ability of tuning significantly the characteristics of the resonant modes correlated to surface plasmons (SPs) propagation along the interfaces of the designed device. By considering two arrangements between LHM and Au, two opposite resonant behaviors observed in p-reflectance spectra are analyzed in the angular interrogation mode and discussed thoroughly.

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-SIZUN, Hervé. "La propagation des ondes optiques visibles et infrarouges dans l'atmosphère terrestre." Revue de l'Electricité et de l'Electronique -, no. 06 (2005): 72. http://dx.doi.org/10.3845/ree.2005.130.

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Shiina, Takahiro, Takuto Maeda, Masayuki Kano, Aitaro Kato, and Naoshi Hirata. "An Optimum 2D Seismic-Wavefield Reconstruction in Densely and Nonuniformly Distributed Stations: The Metropolitan Seismic Observation Network in Japan." Seismological Research Letters 92, no. 3 (February 3, 2021): 2015–27. http://dx.doi.org/10.1785/0220200196.

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Abstract We propose an optimization method for applying the seismic-wave gradiometry (SWG) method to a dense seismic station network consisting of nonuniformly distributed seismographs. As a nonuniformly distributed station array, we consider the station layout of the Metropolitan Seismic Observation Network (MeSO-net) operated in and around the Tokyo metropolitan area, Japan. In this study, thereby, we numerically investigate optimum shapes of weighting functions, which control the spatial weights of individual stations when estimating waveforms at any grid points in the SWG method, to reconstruct seismic wavefields propagating in the MeSO-net. The functions with isotropic spatial weights are found to be appropriate for wavefield reconstructions with seismic waves incoming from practically all directions, even for nonuniformly distributed stations. The reproducibility of the wavefields is greatly improved by changing the shapes of the spatial weights reflecting density of the stations. Further plausible wavefield reconstructions are made by considering the propagation directions of the seismic waves. In these cases, if the weight of a contribution for a wavefield reconstruction is larger at far stations with a direction perpendicular to the wave propagation direction, then the reproducibility of the waveforms is significantly increased. In addition, the spatial gradients of the amplitudes are well reproduced by the optimized SWG method even though the optimization only focused on the amplitudes. Therefore, our proposed optimization scheme can be used to accurately estimate seismic wavefields in a nonuniformly distributed station array. Actually, the weighting functions optimized in this study succeeded to reconstruct the seismic wavefield of a shallow crustal earthquake that occurred around the Tokyo metropolitan area, based on the observed seismograms obtained by the MeSO-net.

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Bonin, J. "COIR AND PEAT: AN OPTIMUM ROOTING SUBSTRATE FOR PROPAGATION©." Acta Horticulturae, no. 1085 (June 2015): 95–98. http://dx.doi.org/10.17660/actahortic.2015.1085.17.

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Li-Min Du, Zi-Qiang Hou, and Qi-Hu Li. "Optimum block-adaptive learning algorithm for error back-propagation networks." IEEE Transactions on Signal Processing 40, no. 12 (1992): 3032–42. http://dx.doi.org/10.1109/78.175746.

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Zhang, Dan, Luciano Leonel Mendes, Maximilian Matthe, Ivan Simoes Gaspar, Nicola Michailow, and Gerhard P. Fettweis. "Expectation Propagation for Near-Optimum Detection of MIMO-GFDM Signals." IEEE Transactions on Wireless Communications 15, no. 2 (February 2016): 1045–62. http://dx.doi.org/10.1109/twc.2015.2482479.

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21

Ueda, H. O., Y. Omura, and H. Matsumoto. "Computer simulations for direct conversion of the HF electromagnetic wave into the upper hybrid wave in ionospheric heating experiments." Annales Geophysicae 16, no. 10 (October 31, 1998): 1251–58. http://dx.doi.org/10.1007/s00585-998-1251-y.

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Abstract. Excitation of upper hybrid waves associated with the ionospheric heating experiments is assumed to be essential in explaining some of the features of stimulated electromagnetic emissions (SEE). A direct conversion process is proposed as an excitation mechanism of the upper hybrid waves where the energy of an obliquely propagating electromagnetic pump wave is converted into the electrostatic upper hybrid waves due to small-scale density irregularities. We performed electromagnetic particle-in-cell simulations to investigate the energy conversion process in the ionospheric heating experiments. We studied dependence of the amplitude of the excited wave on the propagation angle of the pump wave, scale length of the density irregularity, degree of the irregularity, and thermal velocity of the plasma. The maximum amplitude is found to be 37 of the pump amplitude under an optimum condition.Key words. Ionosphere (ionospheric irregularities; plasma waves and instabilities; wave-particle interactions).

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MORFU, S., J. C. COMTE, J. M. BILBAULT, and P. MARQUIÉ. "NOISE-ENHANCED PROPAGATION IN A DISSIPATIVE CHAIN OF TRIGGERS." International Journal of Bifurcation and Chaos 12, no. 03 (March 2002): 629–33. http://dx.doi.org/10.1142/s0218127402004553.

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We study the influence of spatiotemporal noise on the propagation of square waves in an electrical dissipative chain of triggers. By numerical simulation, we show that noise plays an active role in improving signal transmission. Using the Signal to Noise Ratio at each cell, we estimate the propagation length. It appears that there is an optimum amount of noise that maximizes this length. This specific case of stochastic resonance shows that noise enhances propagation.

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Wahaab, Yahya, Shafie, Soleimani, Rostami, and Ganeson. "Determination of Optimum Frequency for Electromagnetic-Assisted Nanofluid Core Flooding." Applied Sciences 9, no. 21 (October 29, 2019): 4608. http://dx.doi.org/10.3390/app9214608.

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The coupling of electromagnetic (EM) wave to nanoflooding experiments, termed EM-assisted nanoflooding has gained enormous attention in recent years. This brings about the consideration of transmitter efficiency and the propagation pattern of the ensuing EM wave, both of which depend on reservoir electromagnetic properties. However, this has not been considered in previous works, despite its potential to improve the efficiency of the process through energy maximization. Hence, this study considers the effects of reservoir EM properties on the operation of a transmitter. The EM properties of saturated reservoir rock samples were measured. Afterward, a half-wave dipole antenna was modeled in a cylindrical reservoir based on the measured EM properties. The EM propagation pattern of the antenna was simulated in a frequency range of 100 MHz—2.0 GHz using the finite element method. The antenna was found to display dual resonance (at 800 MHz and 1.3 GHz) for sandstone saturated with oil, brine and nanofluid. Application of the EM wave at resonance frequency can help increase the efficiency of EM-assisted nanoflooding.

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AHN, WHA-KEUN, BUM KU RHEE, and MYOUNGSIK CHA. "DETERMINATION OF OPTIMUM REFLECTANCE OF OUTPUT COUPLER IN NANOSECOND SINGLY-RESONANT OPTICAL PARAMETRIC OSCILLATOR." Journal of Nonlinear Optical Physics & Materials 20, no. 02 (June 2011): 145–53. http://dx.doi.org/10.1142/s0218863511005930.

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We investigated the signal output efficiency of a singly-resonant ns-optical parametric oscillator based on LiNbO3 with the double-pass pump as a function of reflectance (R) of the output coupler. The measured signal output exhibited a broad maximum around R ~ 35% at a fixed pump energy of 100 mJ/pulse, yielding a maximum signal output efficiency of ~ 38%. The experimental results were well-supported by the numerical calculation using a split-step beam propagation model. We also found that the same beam propagation model with one-dimensional diffraction predicts nearly the same results, enabling fast numerical determination of the optimum reflectance of the output coupler.

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Barauskas, R. "Optimum Mass Matrices for Short Wave Pulse Propagation Finite Element Models." Nonlinear Analysis: Modelling and Control 8, no. 2 (July 25, 2003): 3–25. http://dx.doi.org/10.15388/na.2003.8.2.15180.

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The matrices of a substructure ensuring minimum modal errors of the whole structure are obtained by using optimization approach. The mass and stiffness matrices of a small component domain of selected dimension are obtained by applying the modal synthesis of a limited number of closeto-exact modes such that after assembling a larger joined domain model the modal convergence rate of the latter should be as high as possible. The goal is achieved by formulating the minimization problem for the penaltytype target function representing the cumulative relative modal error of the joined domain and by applying the gradient descent minimization method. After the optimum matrices of a component domain are obtained, they can be used in any structure as higher-order elements or super-elements. The “combined” mass matrices can be treated as a special case of the presented approach. The performance of the obtained dynamic models is demonstrated by solving short wave pulse propagation problems by using a only few nodal points per pulse length.

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26

Yura, H. T. "Optimum truncation of a Gaussian beam for propagation through atmospheric turbulence." Applied Optics 34, no. 15 (May 20, 1995): 2774. http://dx.doi.org/10.1364/ao.34.002774.

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Omenetto, Fiorenzo G., Benjamin P. Luce, and Antoinette J. Taylor. "Genetic algorithm pulse shaping for optimum femtosecond propagation in optical fibers." Journal of the Optical Society of America B 16, no. 11 (November 1, 1999): 2005. http://dx.doi.org/10.1364/josab.16.002005.

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MEISLING, AAGE A. "Om Propagation med “nervus opticus” af Sarkomer, opståede indenfor bulbus oculi." Nordiskt Medicinskt Arkiv 29, no. 1 (April 24, 2009): 1–14. http://dx.doi.org/10.1111/j.0954-6820.1897.tb01385.x.

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Tabakcioglu, Mehmet Baris, and Ahmet Cansiz. "Application of S-UTD-CH Model into Multiple Diffraction Scenarios." International Journal of Antennas and Propagation 2013 (2013): 1–5. http://dx.doi.org/10.1155/2013/285304.

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Propagation prediction models based on ray tracing in coverage estimation for digital broadcasting systems are compared. Geometrical Theory of Diffraction (GTD), Slope Uniform Theory of Diffraction (S-UTD), and Slope UTD with Convex Hull (S-UTD-CH) models are compared for computation time and propagation path loss. S-UTD-CH model is optimum model with respect to computation time and relative path loss.

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Bhatt, Arvind, Christine Stanly, and Chan Lai Keng. "In vitro propagation of five Alocasia species." Horticultura Brasileira 31, no. 2 (June 2013): 210–15. http://dx.doi.org/10.1590/s0102-05362013000200006.

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The influence of cytokinin, N6-benzyladenine, on shoot proliferation of five Alocasia species (A. amazonica, A. cuprea, A. robusta, A. longiloba and A. chaii) was investigated. In vitro propagation of these species was established using shoot tip explants. Murashige & Skoog (MS) medium supplemented with different concentrations of BA (N6-benzyladenine) ranging from 0, 2, 5, 10 mg/L was then used to establish the optimum medium for shoot proliferation for all the species. MS medium supplemented with 2.0 mg/L BA was optimum for the shoot proliferation. All the tested species showed varying results for shoot number and shoot height. A comparison between agar-gelled medium and shake flask system using liquid medium was carried out to evaluate the shoot growth and proliferation for all the tested species. For A. amazonica, A. cuprea, A. robusta and A. longiloba, shake flask system using liquid medium of the same constituents stimulated more shoot proliferation as compared to agar-gelled medium. However, for A. chaii there was no significant difference. All the in vitro plantlets with well developed roots and leaves were successfully acclimatized with more than 90% survival rate.

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Alimboyong, Catherine R. "Modeling virus spread on a network using NetLogo for optimum network management." Indonesian Journal of Electrical Engineering and Computer Science 23, no. 1 (July 1, 2021): 370. http://dx.doi.org/10.11591/ijeecs.v23.i1.pp370-377.

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<span>The infections in computer networks are complex. Its spread is analogous to a contagious disease which can cause destruction within a few seconds. Viruses in a computer or computer networks can spread rapidly by various means such as access to online social networking sites like twitter, Facebook, and opening of email attachments. Thus, infections can go from being little dangerous to significantly harmful for a network. This paper proposed a simulation model that can predict the propagation of virus including the trend and the average infection rate using NetLogo software. Observed and simulated data sets were validated using chi-square tests. Results of the experiment have demonstrated accurate performance of the proposed model. The model could be very helpful for network administrators in mitigating the virus propagation and obstruct the spread of computer virus other than the usual prevention scheme particularly the use of antivirus software and inclusion of firewall security. </span>

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AKHAVAN FARID, A., MOHAMMAD LOTFI, and M. JAHANBAKHSH. "OPTIMUM FLANK WEAR OF TiAlN-COATED TOOL: TOWARD PRODUCTIVE ROUGH CUTTING OF INCONEL 625." Surface Review and Letters 26, no. 08 (September 5, 2019): 1850230. http://dx.doi.org/10.1142/s0218625x1850230x.

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Long tool life and high material removal rate (MRR) are the two essential requirements in rough cutting of materials. The rapid rate of the flank wear propagation in machining of nickel-based superalloys has induced the utilization of low cutting parameters when the goal was set to maximize the tool life based on the machining time or cutting length. However, this method may not provide an effective rate for the material being cut. This work presents two mathematical models to find the optimum cutting parameters results for the minimum flank wear and maximum MRR. Experimental tests were carried out based on the central composite design (CCD) in rough cutting of Inconel 625 by using TiAlN-coated insert. Maximum flank wear was measured to determine the tool wear propagation. The wear mechanisms which contribute in the tool wear were analyzed by using scanning electron microscope (SEM) to evaluate the effects of cutting parameters on the flank wear propagation. The results showed that cutting speed and depth of cut had the most significant effect on the tool wear. However, optimum cutting condition was achieved by reducing the cutting speed when feed rate and depth of cut maintained at the highest level. This was associated to the interaction of cutting speed and depth of cut, and predominant of abrasion and notching at their highest levels, respectively.

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Krishnan, Sarada, and Harrison Hughes. "Asexual Propagation of Shepherdia canadensis and S. rotundifolia." Journal of Environmental Horticulture 9, no. 4 (December 1, 1991): 218–20. http://dx.doi.org/10.24266/0738-2898-9.4.218.

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Abstract Shepherdia canadensis and S. rotundifolia were asexually propagated by hardwood cuttings and aseptic micropropagation. S. canadensis showed greatest rooting of 46.5% with 0.3% IBA. S. rotundifolia showed greater proliferation in woody plant media (WPM) with 0.89 μM BA and optimum rooting in WPM with 5.4 μM NAA.

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Lym, Rodney G. "Propagation ofEuphorbia esulafor Leafy Spurge Biocontrol Agents." Weed Science 40, no. 2 (June 1992): 326–32. http://dx.doi.org/10.1017/s0043174500057428.

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Efforts to screen and mass-rear insects and diseases for leafy spurge biocontrol agents have been hampered by low success in propagation and slow growth of leafy spurge in the greenhouse. The optimum greenhouse conditions for leafy spurge growth were determined. Leafy spurge was propagated from stem tip cuttings, with the basal end treated with 0.2% NAA, and the plants misted with water for 10 d. Optimum conditions for growth were 27 C air temperature, application of a complete fertilizer at 70 kg ha−1weekly or 135 kg ha−1biweekly 20 d after stem tip propagation, in a peat/perlite/vermiculite growth medium at pH 7 and a 16-h photoperiod. Regrowth from roots of parent plants was improved when cuttings were taken from plants at least 60 d old, and plants grew nearly twice as rapidly when the medium was maintained at 30 C compared to 22 C. Refrigeration of stem tip cuttings or roots before planting did not affect survival or growth vigor. Only gibberellic acid of nine plant growth regulators evaluated increased growth, but plants were etiolated. Biotypes from Nebraska and South Dakota were shorter than five others from the United States or Austria but had similar root and shoot dry weight. The time required to propagate vigorous leafy spurge was reduced to 2 mo compared to 6 mo required prior to the study.

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Choi, Hyungseok, JaeYong Lee, and ByungChul Kim. "An Analysis of Optimum Transmission Range in MANETs under various Propagation Models." Journal of Internet Computing and Services 15, no. 2 (April 30, 2014): 1–7. http://dx.doi.org/10.7472/jksii.2014.15.2.01.

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Katsuta, Junichi, Satoshi Kubo, Noboru Konda, Shuhei Koga, Shinichi Ushijima, and Kazuyoshi Kawano. "Retardation Effects of Fatigue Crack Propagation in the Optimum Ferrite-Bainite Steel." Journal of the Japan Society of Naval Architects and Ocean Engineers 12 (2010): 209–17. http://dx.doi.org/10.2534/jjasnaoe.12.209.

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Gutiérrez, Amalia Arzaluz, Francisco Obregón Hernández, and Robert W. Jones. "Optimum Brood Size for Artificial Propagation of the Stingless Bee,Scaptotrigona Mexicana." Journal of Apicultural Research 41, no. 1-2 (January 2002): 62–63. http://dx.doi.org/10.1080/00218839.2002.11101070.

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Sahinoglu, Z., and P. Orlik. "Regenerator versus simple-relay with optimum transmit power control for error propagation." IEEE Communications Letters 7, no. 9 (September 2003): 416–18. http://dx.doi.org/10.1109/lcomm.2003.815661.

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Ivanov, D. V. "Frequency bands for optimum propagation of complex signals through shortwave radio channels." Journal of Communications Technology and Electronics 51, no. 4 (April 2006): 365–72. http://dx.doi.org/10.1134/s1064226906040012.

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Abdollahi, Yadollah, Azmi Zakaria, Nor Asrina Sairi, Khamirul Amin Matori, Hamid Reza Fard Masoumi, Amir Reza Sadrolhosseini, and Hossein Jahangirian. "Artificial Neural Network Modelling of Photodegradation in Suspension of Manganese Doped Zinc Oxide Nanoparticles under Visible-Light Irradiation." Scientific World Journal 2014 (2014): 1–10. http://dx.doi.org/10.1155/2014/726101.

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The artificial neural network (ANN) modeling ofm-cresol photodegradation was carried out for determination of the optimum and importance values of the effective variables to achieve the maximum efficiency. The photodegradation was carried out in the suspension of synthesized manganese doped ZnO nanoparticles under visible-light irradiation. The input considered effective variables of the photodegradation were irradiation time, pH, photocatalyst amount, and concentration ofm-cresol while the efficiency was the only response as output. The performed experiments were designed into three data sets such as training, testing, and validation that were randomly splitted by the software’s option. To obtain the optimum topologies, ANN was trained by quick propagation (QP), Incremental Back Propagation (IBP), Batch Back Propagation (BBP), and Levenberg-Marquardt (LM) algorithms for testing data set. The topologies were determined by the indicator of minimized root mean squared error (RMSE) for each algorithm. According to the indicator, the QP-4-8-1, IBP-4-15-1, BBP-4-6-1, and LM-4-10-1 were selected as the optimized topologies. Among the topologies, QP-4-8-1 has presented the minimum RMSE and absolute average deviation as well as maximum R-squared. Therefore, QP-4-8-1 was selected as final model for validation test and navigation of the process. The model was used for determination of the optimum values of the effective variables by a few three-dimensional plots. The optimum points of the variables were confirmed by further validated experiments. Moreover, the model predicted the relative importance of the variables which showed none of them was neglectable in this work.

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Xu, Yidong, Lili Guo, Wei Xue, Korochentsev Vladimir, and Junwei Qi. "An Optimal Electric Dipole Antenna Model and Its Field Propagation." International Journal of Antennas and Propagation 2016 (2016): 1–8. http://dx.doi.org/10.1155/2016/8601497.

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An optimal electric dipole antennas model is presented and analyzed, based on the hemispherical grounding equivalent model and the superposition principle. The paper also presents a full-wave electromagnetic simulation for the electromagnetic field propagation in layered conducting medium, which is excited by the horizontal electric dipole antennas. Optimum frequency for field transmission in different depth is carried out and verified by the experimental results in comparison with previously reported simulation over a digital wireless Through-The-Earth communication system. The experimental results demonstrate that the dipole antenna grounding impedance and the output power can be efficiently reduced by using the optimal electric dipole antenna model and operating at the optimum frequency in a vertical transmission depth up to 300 m beneath the surface of the earth.

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Śmigielski, Grzegorz, Wojciech Toczek, Roman Dygdała, and Krzysztof Stefański. "Metrological Analysis of Precision of the System of Delivering a Water Capsule for Explosive Production of Water Aerosol." Metrology and Measurement Systems 23, no. 1 (March 1, 2016): 47–58. http://dx.doi.org/10.1515/mms-2016-0006.

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Abstract In this paper precision of the system controlling delivery by a helicopter of a water capsule designed for extinguishing large scale fires is analysed. The analysis was performed using a numerical method of distribution propagation (the Monte Carlo method) supplemented with results of application of the uncertainty propagation method. In addition, the optimum conditions for the airdrop are determined to ensure achieving the maximum area covered by the water capsule with simultaneous preserving the precision level necessary for efficient fire extinguishing.

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Dang, Mingxia, Jiaji Wu, Shengcheng Cui, Xing Guo, Yunhua Cao, Heli Wei, and Zhensen Wu. "Multiscale Decomposition Prediction of Propagation Loss in Oceanic Tropospheric Ducts." Remote Sensing 13, no. 6 (March 19, 2021): 1173. http://dx.doi.org/10.3390/rs13061173.

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The oceanic tropospheric duct is a structure with an abnormal atmospheric refractive index. This structure severely affects the remote sensing detection capability of electromagnetic systems designed for an environment with normal atmospheric refraction. The propagation loss of electromagnetic waves in the oceanic duct is an important concept in oceanic duct research. Owing to the long-term stability and short-term irregular changes in marine environmental parameters, the propagation loss in oceanic ducts has nonstationary and multiscale time characteristics. In this paper, we propose a multiscale decomposition prediction method for predicting the propagation loss in oceanic tropospheric ducts. The prediction performance was verified by simulating propagation loss data with noise. Using different evaluation criteria, the experimental results indicated that the proposed method outperforms six other comparison methods. Under noisy conditions, ensemble empirical mode decomposition effectively disassembles the original propagation loss into a limited number of stable sequences with different scale characteristics. Accordingly, predictive modeling was conducted based on multiscale propagation loss characteristic sequences. Finally, we reconstructed the predicted result to obtain the predicted value of the propagation loss in the oceanic duct. Additionally, a genetic algorithm was used to improve the generalization ability of the proposed method while avoiding the nonlinear predictor from falling into a local optimum.

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Harvey, Michael P., and Mark H. Brand. "103 Optimizing the Propagation of the Ornamental Grass Hakonechloa macra `Aureola'." HortScience 34, no. 3 (June 1999): 459B—459. http://dx.doi.org/10.21273/hortsci.34.3.459b.

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Studies initiated in Spring 1998 analyzed the influence of division size, shade, and temperature on the growth rate of the ornamental grass Hakonechloa macra `Aureola' in nursery-container production. To determine the optimum division size for production, container-grown stock plants were used to make early spring divisions of four sizes (1-2, 4-6, 8-10, and 12-15 buds). Divisions were established in 325-ml pots for 1 month before being transplanted to 3.7-L nursery containers. Plants were grown outdoors and received topdressed 17-6-10 slow-release fertilizer (containing micronutrients) and drip irrigation from June through September. Average leaf area, shoot number and bud count increased linearly as division size increased, but average height remained the same between each treatment. Plants of all division sizes exhibited healthy growth, with 50% of the plants in the 4-6 buds/division treatment growing to marketable size compared to 45%, 35% and 15% in the 8-10, 12-15, and 1-2 buds/division treatments, respectively. Four shade densities (0%, 30%, 50%, and 70%) were tested to determine which promoted optimum growth. As shading increased, average shoot number per plant decreased, average height and shoot length increased and bud count remained the same. To determine the optimum growing temperature for Hakonechloa, divisions were grown in 325-ml pots under four different day/night temperatures (15/10, 21/16, 27/22, and 33/28 °C) for 12 weeks in growth chambers. Plants were fertigated daily with a 5-25-5 liquid fertilizer. Average bud count, leaf area, plant height, plant width, shoot length, and shoot number increased as temperature increased to 27/22 °C, then decreased significantly beyond this temperature optimum.

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VINOJ, M. N., A. U. SEEMA, and V. C. KURIAKOSE. "OPTIMUM DISPERSION PROFILE AND PEDESTAL-FREE SOLITON PULSE COMPRESSION IN DISPERSION-DECREASING FIBER." Journal of Nonlinear Optical Physics & Materials 12, no. 03 (September 2003): 291–305. http://dx.doi.org/10.1142/s0218863503001432.

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We propose soliton pulse compression mechanism in a dispersion decreasing fiber for the integrable case. We have studied the pulse propagation through various dispersion-decreasing profiles in the adiabatic approximation limit. Out of the different profiles studied, Gaussian profile is found to be the best choice for achieving maximum pulse compression and is found that compressed pulse is completely free from pedestals.

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Li, Xiaolong, and Jiayuan He. "Research and Application of Radial Borehole Fracturing Based on Numerical Simulation." Geofluids 2019 (November 20, 2019): 1–16. http://dx.doi.org/10.1155/2019/2167094.

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The radial borehole fracturing technology has been applied in a certain number of oilfields with good results being achieved. However, the morphology and variation of fracture still require further study. In this paper, the reservoir model based on formation fluid-solid coupling equation is established with the extended finite element method (XFEM) in ABAQUS, and the fracture morphologies in the single-radial borehole, vertical multiradial borehole, and horizontal multiradial borehole are simulated and analyzed with criteria of maximum principal stress and maximum energy release rate as the damage mechanism. Moreover, the accuracy of numerical simulation results is verified with the large-scale true 3D physical simulation experiment. The results show that the induced stress field along the radial borehole during fracturing is the root cause of fracture directional propagation along the radial borehole whose effective guidance distance reaches 40 m. The vertical multiradial borehole can effectively enhance fracture directional propagation and is capable of reducing fracture initiation pressure. In the horizontal multiradial borehole, the major fracture propagating along each radial borehole is formed in the remote-borehole area, and the secondary fracture connecting the neighboring radial boreholes is formed in the near-borehole zone. Coordination of major and secondary fractures can effectively increase the drainage area and reduce the flow resistance in the near-borehole zone. Based on the research on fracture morphology of multiradial borehole fracturing, the scheme of radial borehole arrangement is optimized and verified through numerical simulation of deliverability. The final optimum borehole arrangement scheme is the intersectional angle of 45° between four orthogonal radial boreholes and horizontal maximum principal stress.

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Yenice, Y. E., and B. G. Evans. "Optimum beam size for laser beam propagating through atmospheric turbulence." Electronics Letters 35, no. 21 (1999): 1875. http://dx.doi.org/10.1049/el:19991276.

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Jinghu Chen and M. P. C. Fossorier. "Near optimum universal belief propagation based decoding of low-density parity check codes." IEEE Transactions on Communications 50, no. 3 (March 2002): 406–14. http://dx.doi.org/10.1109/26.990903.

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ZHAO, W., Z. L. JIANG, H. R. YU, T. SAITO, and K. TAKAYAMA. "WAVE PROPAGATION ANALYSIS IN A PRESSURE-WAVE-REFRIGERATOR." Modern Physics Letters B 19, no. 28n29 (December 20, 2005): 1747–50. http://dx.doi.org/10.1142/s0217984905010372.

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Pressure wave refrigerators (PWR) refrigerate the gas through periodical expansion waves. Due to its simple structure and robustness, PWR may have many potential applications if the efficiency becomes competitive with existing alternative devices. In order to improve the efficiency, the characteristics of wave propagation in a PWR are studied by experiment, numerical simulation and theoretical analysis. Based on the experimental results and numerical simulation, a simplified model is suggested, which includes the assumptions of flux-equilibrium and conservation of the free energy. This allows the independent analysis of the operation parameters and design specifics. Furthermore, the optimum operation condition can be deduced. Some considerations to improve the PWR efficiency are also given.

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Luo, Qiang, and Qing Li Ren. "Application of Improved Back-Propagation Neural Network and Genetic Algorithm to the Preparation Processing of the Mg,Al-Hydrotalcite/Polymer Nanocomposite." Key Engineering Materials 368-372 (February 2008): 1680–82. http://dx.doi.org/10.4028/www.scientific.net/kem.368-372.1680.

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The three-layer structure back-propagation network model based on the non-linear relationship between the break percentage elongation of the Mg,Al-hydrotalcite/PE nanocomposites and the technological factors was established. And in order to accelerate the converging rate and avoid the local minimum, dimensionality reduction and pre-whitening methods were used. Moreover, the optimum technological process parameters were optimized with genetic algorithm. And the results show that using both the back propagation neural networks and genetic algorithm is very efficient for the prediction of the break percentage elongation of the Mg,Al-hydrotalcite/PE nanocomposite.

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Journal articles on the topic 'Propagation Optique'

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